The above-identified applications are incorporated herein by reference.
In the accompanying drawings:
FIG. 1 illustrates an embodiment of the instant invention;
FIG. 2 illustrates a child in a typical rear facing infant seat placed on a vehicle seat;
FIGS. 3a and 3b illustrate several electrode embodiments in accordance with the instant invention;
FIG. 4 illustrates another electrode embodiment in accordance with the instant invention;
FIG. 5 illustrates yet another electrode embodiment in accordance with the instant invention,
FIG. 6 illustrates the capacitance of an electric field sensor in accordance with FIG. 5 for a variety of seat occupancy scenarios and conditions;
FIG. 7 illustrates a side-view of an embodiment of an electric field sensor incorporating a driven shield;
FIG. 8 illustrates a schematic diagram of an embodiment of a circuit for providing both amplitude and phase information from an electric field sensor;
FIG. 9 illustrates a plot of phase angle vs. amplitude of an electric field sensor for a variety of seat occupancy scenarios and for varying degrees of wetness;
FIG. 10a illustrates a schematic diagram of another embodiment of a circuit for providing both amplitude and phase information from an electric field sensor;
FIG. 10b illustrates the operation of various elements of the sensing circuit of FIG. 10a; 
FIG. 11a illustrates a flow chart of the processing of amplitude and phase measurements from an electric field sensor;
FIG. 11b illustrates a flow chart of a process of calculating a rotation factor from amplitude and phase measurements from an electric field sensor for dry seat conditions;
FIG. 11c illustrates a flow chart of a process of calculating a compensation function from amplitude and phase measurements from an electric field sensor;
FIG. 12a is a plot of phase vs. amplitude for measurements from an electric field sensor for dry seat conditions, illustrating a rotation angle for adjusting subsequent measurements from the electric field sensor;
FIG. 12b is a plot of phase vs. amplitude for measurements from an electric field sensor for a variety of seat occupancy conditions and a variety of seat wetness conditions;
FIG. 12c is a plot of a compensation function;
FIG. 12d is a plot of compensated amplitude as a function of rotated phase for the measurements of FIG. 12b; 
FIG. 13a illustrates a plurality of capacitance measurements from an electric field sensor, plotted as a function of wetness for a variety of seat occupancy scenarios;
FIG. 13b illustrates a plurality of capacitance measurements from an electric field sensor, compensated in accordance with the process of FIG. 11a, plotted as a function of wetness for a variety of seat occupancy scenarios;
FIGS. 14a and 14b illustrate a schematic diagram of yet another embodiment of a circuit for providing both amplitude and phase information from an electric field sensor;
FIG. 15 illustrates a schematic diagram of an embodiment of a circuit for providing both integral and peak information from an electric field sensor using pulse excitation;
FIG. 16 illustrates a schematic diagram of another embodiment of a circuit for providing both integral and peak information from an electric field sensor using pulse excitation; and
FIG. 17 illustrates signals in the circuit of FIG. 16 for two different levels of shunt resistance of the electric field sensor.